Sunken Treasures of the Nile

In November of 2008 xRez Studio was asked to join Insight Digital on an expedition to Egypt to help create a documentary for the French Channel 3 Television show “Le secret des Pharaons bâtisseurs” on “Des Racines & Des Ailes” directed by Frédéric Wilner. Now there is an American version of this film on the National Geographic Channel called “Sunken Treasures of the Nile” The show will be airing August 3rd 2010 at 1PM, and November 8th 2010 at 4pm.

xRez was initially invited to provide photogrammetry (3D reconstruction from photographs) for the post production of visual effects. The visual effects would be used to explain the theories explored in the film of how various monuments were moved from the quarries to the cities where they would be installed downstream along the Nile. The plan was to use an experimental method that would rely on Microsoft’s Photosynth to generate CG versions of the terrain and monuments that would have to be rendered due to not being able to get good aerial footage in areas that had closed airspace. Mark Eakle of Insight Digital and Xenexus was providing Kite Aerial Photography (KAP) to assure we had good high angle photos of the surrounding terrain. Read more about the Photogrammetry from KAP in this blog post. During the shoot we found that Photosynth did an exceptionally good job at recovering point clouds of objects of multiple scales from small sculptures to large terrain elements that were too large for the project’s more accurate laser scanners.

Photosynth played an unexpected role in the film. We initially were using Photosynth only to recover the point clouds and camera poses for creating 3D models, however we found that from the extracted point clouds we were able to create models and test the theories that the Egyptologist Philippe Martinez, the director Frédéric Wilner, and Kevin Cain from Insight Digital came up with during the day. By photographing the sites while the film crew filmed these experts we were able to test some of their theories in 3d by the evening, Photosynth not only played a role in the post for the film but was used in the film directly. In the evenings on a boat moored just off from the site we would process the Photosynth, capture the point cloud and Jun Nagaoka of Insight Digital would mesh the point cloud into a 3d model so we could test the various theories that the experts had come up with during the day. The film crew would set the cameras up behind the computers and now the freshly made models and photosynths became part of the documentary process.

Stela “M”

One especially exciting moment in the process came after a long day of filming in the quarries when Philippe Martinez was taking a new route back to the boat through some talus fields. He noticed that there were a large number of small boulders rolled under a larger boulder. This seemed like a strange configuration and upon rolling them out he found there was a Stela with hieroglyphics on them. To his surprise there was a visual description of how the monuments were moved from the quarries onto the boats. This was a huge discovery! Documentation of how the Egyptians moved these massive monuments (i.e. 1000 ton Obelisks) from the quarries onto boats has never been found before. Until now Egyptologists and others had just had to take educated guesses as to how these were moved. Philippe called Fredrick and the rest of the team on the radio and the film crew came rushing over to film the new discovery. We were also able to capture images for a Photosynth during these exciting first few moments. Next we wanted to get as detailed of a documentation as possible, Carlos Velazquez of Epic Scan provided the laser scanning and xRez worked with Mark Eakle to produce a Polynomial Texture Map (PTM) (below) that allows you to virtual relight the image to better study the surface of the carving.

UPDATE: In addition to the photosynth (above) and the re-lightable PTM (below) we have also extracted a gigapixel orthographic texture using photogrammetry. You can read more about it and view it interactively in this blog post on “Photogrametric Gigapixel Images”.